It's a way of expressing joy or happiness in response to good news. The phrase is often used in casual conversations and is considered a friendly and polite way to react to positive news.
Here's a breakdown of the phrase:
* Que bueno: This means "That's great" or "How good."
* Me alegro: This means "I'm glad" or "I'm happy."
The phrase is often shortened to "Me alegro" in informal situations.